1. Field of Invention
This invention relates to electronic communication and, in particular, to a method and system for communicating DisplayPort™ information.
2. Description of Related Art
DisplayPort™ information is any information that is expressed in accordance with the specification of the DisplayPort standard. The DisplayPort standard provides specifications of connectors, cables and data communication protocols for use in delivering uncompressed digital packetized video streams from a computer host to a display and in bi-directionally communicating control data between the computer host and the display. However, the DisplayPort specification is limited to communicating such control information by a half-duplex protocol in which bi-directional control signals are communicated one way at a time along a single, common communication medium. Also, the permitted range between the computer host and the display is limited by the DisplayPort specification timeout requirement, such that the computer host will time-out if a response from the display is not received within 300 microseconds following the delivery of control data from the computer host to the display.
United States patent application publication No. 2008/0240152 attributed to Quinn et al. discloses a system and method for communicating data for display on a display device. Quinn et al. disclose that in operation, a host device transmits a first set of DisplayPort data to a converter. The first set includes uncompressed DisplayPort data and/or control data for controlling the display device (e.g. turning the display device “on” or “off” or adjusting the brightness, contrast, tint or color of the display device). The converter converts the first set into network packets, which are transmitted via a data network and then converted into a second set of DisplayPort data for routing to the display device. However, the disclosure of Quinn et al. is limited to communicating control data in the direction from the host device to the display device for controlling the display device, and fails to address the effect of the timeout requirement of the DisplayPort specification on the permitted range between the host device and the display device.
United States patent application publication No. 2008/0279186 attributed to Winter et al. discloses a system and method for the communication of uncompressed visual information through a network. Winter et al. disclose that a packet converter switch encapsulates uncompressed visual information received from an information handling system into network packets and then communicates the network packets through one network port to traverse a conventional network architecture to reach a network port of a second packet converter, where the uncompressed visual information is extracted for communication through a DisplayPort port to a display device. Winter et al. disclose that bi-directional DisplayPort functions are supported by reference to mapping information on a packet converter switch to correctly switch information sent from a sink to a source device. Winter et al. disclose that such bi-directional DisplayPort functions include the communication of EDID information from the display device to the information handling system. However, the disclosure of Winter et al. is limited to the support of DisplayPort functions, and fails to address the effect of the timeout requirement of the DisplayPort specification on the permitted range between the information handling system and the display device.
United States patent application publication No. 2009/0003331 attributed to Winter et al. (the '331 publication) discloses a system and method for adding a transport layer to uncompressed visual information packets, in which a DisplayPort source creates a unique identifier associated with a sink device and a packet stuffer associated with the DisplayPort source adds the unique identifier to each DisplayPort packet. The packets are sent to the targeted sink device by reference to the unique identifier, including sending packets to distal locations through networks. However, the disclosure of the '331 publication is limited to adding the unique identifier to each DisplayPort packet, and fails to address the effect of the timeout requirement of the DisplayPort specification on the permitted range between the DisplayPort source and the targeted sink device.
U.S. Pat. No. 6,381,666 attributed to Kejser et al. discloses a method and apparatus for transmitting a data stream between a host controller and a peripheral device over an extended distance. However, the disclosure of Kejser et al. fails to address the communication of DisplayPort information.
U.S. Pat. No. 7,149,833 attributed to McLeod discloses a method and apparatus for extending the range of standard USB (Universal Serial Bus) devices and, in particular, USB devices operating in accordance with Revision 2.0 of the USB Specification. However, the disclosure of McLeod fails to address the communication of DisplayPort information.
U.S. Pat. No. 7,493,431 attributed to McLeod (the '431 patent) discloses a method and apparatus for extending the range of the USB protocol by an expanded range host controller in combination with a remote extender located adjacent to a peripheral device. The expanded range host controller provides extended time values for responding to the USB protocols, while the remote extender provides for data transmissions with the peripheral device which comply with the USB protocols. However, the disclosure of the '431 patent fails to address the communication of DisplayPort information.